


Song of the Abyss

by Tookette



Category: Uta no Prince-sama
Genre: A little spooky, Alternate Universe - Fantasy, Angst, Fairy Tale Elements, Grief/Mourning, I'll update the tags as I go, M/M, Magic and Alchemy, Night Terrors, Sleepwalking, Slow Burn, fairytale AU, kingdom au, princes au, the character death is just mentioned
Language: English
Status: In-Progress
Published: 2019-11-04
Updated: 2019-11-19
Packaged: 2021-01-22 22:54:49
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 3,646
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21309964
Author URL: https://archiveofourown.org/users/Tookette/pseuds/Tookette
Summary: Ever since the death of his bestfriend, Prince Reiji's sleep has been... chaotic at best. An unexpected visit from the neighbouring kingdom will only make matters worse..."Come to me, Reiji...""I miss you..."
Relationships: Kotobuki Reiji/Mikaze Ai
Comments: 18
Kudos: 16





	1. The letter

* * *

_Come to me. _

_Come to me. _

He was floating. His steps were light, bare feet barely feeling the floor beneath him. He was walking on air.

_Follow my voice. _

_Come to me. _

The voice echoed in his mind, calling him, pulling him through space and time. It came from everywhere and nowhere at once, surrounded him, but still, his feet carried him forward. As if he knew exactly where he was going, where the voice was coming from.

_Come to me, Reiji. _

_Come to me._

So he walked. Or floated. He wasn’t sure which he was doing, but he was moving forward, one step at a time, entranced like a moth by the lantern’s light. Like a ship by the lighthouse’s beacon. Only his light was a voice, such a sweet voice, a terrible voice that he both loved and hated.

_Come to me. Reiji._

_Reiji._

_Reiji._

_“Prince Reiji!”_

* * *

“REIJI!”

Reiji’s eyes snapped open and his legs gave way beneath him. He would have collapsed were it not for a pair of strong arms wrapping around his legs and torso. A stern face appeared above him, pink and grey eyes filled with concern locked onto him as he was lowered to the cold stone floor. The window behind him was dark. Torches were burning on the walls. It was night-time and he was in the middle of the stone corridor.

“… was I sleepwalking again?” He asked, his voice sounding a little fuzzy. The man’s frown deepened.

“You were.”

“… sorry.”

The Captain of the guards helped him sit up, one hand planted firmly between his shoulder blades to prevent him from falling backwards should he feel weak again.

“I’m okay, Ran-Ran. Just a headache.”

“Mmm…”

The man didn’t seem any less concerned, but who could blame him, really? What was it? The second time this week? Sixth time this month? And, wait… did he actually make it down the stairs this time? He let his eyes blearily stare at the closest tapestry. One of his favourites, a tree with leaves of the deepest green, showered by sparkling stars and surrounded by candles. Definitely one of the ground floor decorations.

His room being four floors up, this was a concern.

“I’m surprised I didn’t kill myself in the staircase.” He chuckled to lighten the mood.

Ranmaru’s sigh confirmed that his joke fell short.

“Maybe you got lucky… I’ll make sure you won’t be able to reach the stairs, next time.”

The guard stood up and offered his charge a hand up, which Reiji gladly accepted. He was still a little wobbly legged, but at least he could stand.

“Didn’t I tell you to lock your room for the night?”

“I did!”

“You should have taken the key out!”

“I did!”

Ranmaru deepened his frown as he led the older but smaller man back to his room. They had to slow down as they trudged up the stairs, Reiji’s trembling legs making their progress difficult.

Usually, the Captain would leave him once he’d passed the doors to his chambers. This time, however, he followed him inside to check on the door. Sure enough, the key was still attached to the keyhole. He immediately took it out.

“Where’d you put it?”

Reiji didn’t answer, he just walked up to a set of drawers. The top drawer was already open, so was the jewellery box inside. His sleepwalking self didn’t feel like tidying up after getting the key, so it would seem.

Ranmaru sighed and pocketed the key.

“Starting now, I’m locking you in for the night. Okay?”

Did he really have a choice at this point? Ranmaru was right. He got lucky with those stairs, one misstep could have easily led to a broken neck.

At least, if there was one person in this goddamned castle he could trust with his life and sanity, it was the silver haired Captain. So, he responded to his enquiry with a nod, closed both jewellery box and drawer and trudged back to bed. The sheets had gone cold again, so he pulled his legs to his chest, tucking his freezing feet against his body for some warmth.

Slippers. His sleepwalking self couldn’t even be bothered by slippers.

“I’ll come get you come morning. If you need anything…”

“I’ll call. Don’t worry, I never sleepwalk twice in a row.”

“You never reached the ground floor before, either.”

“True, but luckily I have my faithful Ran-Ran to save me from the cold.”

He heard a sneer behind him. It brought a smile to his face.

“Whatever. Goodnight.”

“Goodnight Ran-Ran.”

Ranmaru’s footsteps left the room. The door closed, he could hear the key turning once, more footsteps, fading away...

Then there was silence.

He glanced out the window. The sky was still dark, the moon was high over the cliffs. If he listened closely, he could hear the waves crashing in the distance.

He hated that sound.

He didn’t get much sleep that night.

* * *

_Come to me, Reiji._

_I miss you._

* * *

Ranmaru had no idea how the Prince did it.

He’d seen the bags beneath his eyes come morning, when he came to free Reiji from his chambers. The older man didn’t get much more sleep than he did, if at all.

Despite this, there he was, smiling at the maids, joking with the servants, bouncing around with the good mood of an energetic child about to go on an adventure.

Where he managed to find all that positive energy, cranky Ranmaru didn’t know.

“Ran-Ran should take some coffee!” Reiji suddenly said as he appeared in front of him, a steaming cup in his hand. The Captain groaned but didn’t push away the offer, nose wrinkling as he sipped the bitter liquid. His Prince’s smile grew bigger before he bounced his way back to the breakfast table.

Not to say he was surprised. Reiji had always been like this. He ignored the concerned looks servants were throwing his way (because of course everyone knew about what happened last night, Ranmaru had chewed out the guards supposed to patrol the Prince’s corridor). He made a show of his good mood, reassured everyone that he was okay.

He was okay.

* * *

Until mid-afternoon that day.

Ranmaru studied Reiji’s crumbling face as his eyes darted across the letter young Tokiya had just brought in. The broken crest had borne the neighbouring kingdom’s colours, ones neither the Captain nor the Prince had been expecting.

Once Reiji brought the letter down, Ranmaru held out his hand. The Prince yielded the missive easily, allowing him to skim the contents that had managed to break his mood.

The further he read, the more his brow furrowed. He could hear Reiji’s fingers twitching against his chest.

“… I wasn’t aware Prince Aine had a younger brother.” He finally said, once he’d reached the end of the letter.

“Neither was I.”

“I take it Prince Aine never mentioned him?”

Reiji shook his head. His fingers curled tighter in the fabric of his shirt.

“… you can’t afford to turn them away, you know?”

“I know.”

“Will you be alright?”

“Of course.”

A lie. They both knew Reiji wasn’t going to be fine.

* * *

_To his Highness, Prince Reiji. _

_Please forgive my lack of exchange. I fear my beloved son’s death has taken a toll on me. Although this tragic event should not have impacted on my duties as an ally, my grief has been unbearable and I suspect the same could be applied to you, for I know how close you were to my beloved Aine. _

_Nonetheless, however cruel this may sound, it is time for us to move forward. My Aine would have never wanted us to grieve eternally._

_In order to rekindle the alliance between our two kingdoms, it would be my pleasure if you could grant an audience to my second son, Prince Ai. He is very eager to meet you, the Prince his brother wouldn’t stop talking about. _

_By the time this letter reaches you, Prince Ai should be on his way. The ship bearing him should reach your port by Friday night._

_I look forward to hearing more from you and your kingdom. It is my wish that our two kingdoms should come back together as allies, the way it was before the accident. Hopefully, the friendship you shared with my Aine should pass on through Prince Ai._

_Best regards._

_His Majesty, King Kisaragi._

* * *

Friday came too soon, for Reiji.

Ever since Tokiya came into his office with the fateful letter, the castle had been bustling with activity in preparation for the Prince’s arrival. The servants were rushing in and out, supplying the kitchens with the finest food with which to cook extravagant meals. Lords and ladies were invited in a hurry to greet the Kisaragi heir, the ballroom was being decorated with the most beautiful seasonal flowers, and the castle’s best guest room was being thoroughly cleaned for their esteemed guest.

(Reiji tried not to think of it as Aine’s room. It had not been used since last he came. Since he died.)

Friday came, and he was waiting on the docks.

Tokiya and Otoya were standing right behind him, in their finest clothes. As the ship came into view and slowly made its way closer, Reiji could hear Tokiya muttering reassurances to the younger teen. Even with his back turned to them, the Prince knew Otoya well enough to confidently assume the boy was almost as red as his hair, nervous of his rather new position as the advisor’s right-hand man. He couldn’t really blame him, it was the first official visit he was attending, and it was royalty.

He focused on their low voices, drowning out the sound of the seagulls calling and the waves crashing. When Otoya finally calmed down enough for them to be quiet, he almost begged for them to start talking again. Almost.

Slowly the ship sailed closer, slowly, slowly. When it finally reached the docks, sailors started shouting and running around, until the boardwalk was settled, allowing the foreign Prince to finally set foot on solid land.

The moment he saw aqua hair, Reiji’s ears started ringing and his vision started blanking out at the edges. His chest hurt, his legs suddenly felt like jelly and he wanted to scream with no air.

He didn’t see Prince Ai. He saw Prince Aine’s ghost.


	2. The spare

**Summary for the Chapter:**

> Prince Reiji gets to meet Prince Ai.

_I miss you..._

_**… ji…** _

_I miss you so much…_

** _... Rei…_ **

_Come find me …_

** _Prince Reiji!_ **

* * *

Reiji blinked. His vision filled with red. Red hair, red eyes, a warm face, a worried voice calling to him through the ringing in his ears. It took him a moment to realise that not only was he lying on the ground, he was also staring at young Otoya’s concerned face.

He sat up with a groan, hand rapidly going to his aching head. Other hands, more than just one set, came to rest on his back and shoulders to steady him.

“What… what happened?”

“You collapsed.” Tokiya’s worried voice came from right behind him. Hands. On his back and shoulders. Ah, so Otoya hadn’t grown an extra set of hands after all…

“Can you stand?” It came from before him? Above him? It was Otoya’s voice. Maybe he should focus…

Stand… Yeah, standing sounded like a good idea. Good place to start.

“Yeah… I can stand.”

He couldn’t.

The hands gripping him from behind tightened. Tokiya (yeah, it must be Tokiya, he heard a grunt, much softer than the one his captain usually makes). Tokiya wasn’t buying it.

He tried anyways. Held onto Otoya’s shoulders to keep his balance and tried hoisting himself up.

His legs kept wobbling.

“Move over!” Grunted a voice, much gruffer than the others. There was movement at his side, someone shoving people away (people… when did it get so crowded? Oh, right, he collapsed in front of everyone, everyone must be worried).

The hands helping him up suddenly disappeared and his wobbly legs gave out. Luckily, strong arms caught him mid-fall and he was hoisted up against a metal torso, a metal shoulder.

“Hey Ran-Ran…” He wheezed before closing his eyes. No use keeping them open. He couldn’t focus on anything.

“I’m taking him inside. Tokiya, you take care of the…”

“Make way! Make way, peasants!”

Huh… he couldn’t place that voice. Never heard it before. He tried peaking his eyes open, but his vision was blurry.

“Sir.” Tokiya. That was Tokiya’s no-nonsense voice. “Please stand back, Prince Reiji is…”

“Are you deaf? I’ve asked you to move, peasant!”

“That is quite enough, Camus.”

Who’s Camus?

Wait…

That last voice…

It couldn’t be…

“Aine…?” Once again, Reiji tried opening his eyes, tried lifting his head from Ranmaru’s shoulder to look in the direction the new voices were coming from.

Focus. Focus.

His blurry eyes found Tokiya and Otoya’s backs. Both were standing in the way of a tall, angry looking blond man. At his side was… Aine?

Impossible. Aine was dead.

Aine was looking straight at him.

“Is Prince Reiji going to be okay?”

… was he going to be okay?

… maybe?

…or maybe not.

He fainted.

* * *

_I miss you so, so much…_

_Come to me…_

_Reiji…_

_Come find me…_

* * *

When next he came to, he was lying on one of the many comfortable sofas of his most used living room, the one adjoining the room he usually used to receive important guests.

Ranmaru was standing watch beside one of the armrests with his arms crossed, glare fastened on one of the doors in front of him.

“Ran-Ran?”

As soon as he heard his voice, the captain’s heterochromatic eyes fell on him and his features softened just the slightest.

“Feeling better?” He enquired, dropping his arms to be able to stretch out a hand. Reiji gratefully accepted his offered help.

“Headache…” It came out as a croak and Reiji could hardly recognize his own voice.

The Captain’s water pouch appeared in front of his face and large hands helped tilt his head back so he may take a sip.

“Careful, now.” Groaned the younger man. “Don’t choke on me, now.”

Easy for him to say. His throat felt itchy and dry.

Still, he managed to sip some of the water without choking.

Once his thirst was quenched, Reiji swung his legs over the side of the couch to rest his feet on the floor. Ranmaru’s stare turned into a slight glare.

“Are you sure you’re ready to stand?”

“I’m fine, Ran-Ran.”

“No, you’re not. Do you even remember what happened?”

What happened?

He was standing on the pier. He could hear Otoya and Tokiya behind him. He had been stressed because…

Because…

Prince Ai was supposed to arrive today.

Had he been so stressed that he passed out?

He heard a sigh over him and a hand appeared before his face. He took it, gladly, and used it as leverage to stand.

“I have to warn you before this shit happens again.” Ranmaru said. “You passed out twice when you saw Prince Ai.”

When he saw…?

He’d seen Prince Ai?

“What? Why? I can’t even remember what he…”

“He looks exactly like Prince Aine.”

Oh.

OH!

That explained it.

“I… thought it was him, didn’t I?”

“I can only assume that’s what happened.” Ranmaru’s hand was keeping him steady, while his other arm wrapped gently around his back. “I have to admit I did a doubletake when I saw him. He doesn’t wear his hair the same way, though. And he… sounds a little different.”

Now he remembered.

He remembered seeing the boy walking up to the gangplank. Remembered hearing his voice, asking if he was alright. Remembered seeing him, standing beside an unknown blond man.

He looked so much like Aine.

Only it wasn’t Aine.

It was Ai.

Aine’s unknown little brother.

“At least now I have a heads-up.” Reiji remarked rather dryly. His throat still itched but it was a lot more bearable, now.

He heard Ranmaru’s rumble, the one that sounded like an assent. He felt it, too; his captain had pulled him against his side, his chest now devoid of his metal armour.

His light-headedness had cleared for the most part. His legs weren’t wobbling anymore. He was steady on his feet, though it kind of unnerved him to know he’d have to release Ranmaru’s hand, sooner or later.

Sooner or later, he will have to face Ai properly. To welcome him. And remind himself, constantly, that he wasn’t Aine.

“Where is he? Where is the Prince?”

Ranmaru’s arm tightened around him.

“Reiji…”

“I can’t hide forever, Ran-Ran. I’d be a very poor host if I can’t even be bothered to see my guest.”

The taller man sighed.

“You sure you’re ready?”

A dry laugh. Of course he wasn’t.

“Nah. But let’s get this over with.”

He inhaled deeply then stepped away from his captain.

* * *

Prince Ai, it turned out, was Aine.

But then again, he wasn’t.

Now that he could see him from up close, Reiji could see the little things that made him so very different from his Aine.

The hair colour was off, if only by a shade or two. His eyes were bigger and lighter. The way he held himself was wrong, his posture too straight. His voice was the same (it unnerved Reiji so much) but his tone… it didn’t hold as much emotion.

The more he stared (his sister would have scolded him by now, had she been here), the more he saw the differences, the easier it was to realise that this man, this boy (he couldn’t be older than 20, the age Aine left, the age he had when he…) was nothing like his Aine.

While Ranmaru had taken his unconscious form to the living-room, Tokiya and Otoya had led Prince Ai and the mysterious blond man accompanying him to the room next door, where they’d been treated with the utmost respect one would expect royal guests to be treated. He really was blessed to have Tokiya at his side: the boy took his role as advisor very seriously and was determined to fulfil his job as fervently as possible. He knew aspects of the court life that had bored Reiji so much during his studies he could barely remember the half of it. But not Tokiya. Tokiya took everything seriously. A bit too much, even.

When Reiji entered the room, Tokiya immediately stood up to announce his presence and lead him to their guests.

“How are you feeling, your Highness? I did warn you leaving the castle without a hat would be a bad idea, especially with how hard the sun was beating down on us!”

Did he? Reiji couldn’t remember.

Oh.

Right.

Tokiya you genius!

He’d told their guests he’d collapse because of a heatstroke.

“I’m feeling much better, thank you Tokiya.” It was hard not to beam at his young friend for the perfect excuse he’d supplied him, but he managed somehow. He then turned to their guests, Prince Ai and who he discovered later to be Camus, his trusted advisor. “Please excuse the poor display from earlier, your Highness. I fear I may have underestimated the sun’s destructive powers.”

_Ai. His name is Ai. He looks like Aine but he’s not Aine._

He repeated this mantra, over and over again. He had to. He didn’t want a repeat of what happened on the pier.

“Yes, standing so long beneath the sun was indeed a poor choice, your Highness.” Ai bluntly replied, to Reiji’s surprise. Aine had never been THAT blunt, even when they were close. “But I am happy to see you back on your feet, although you do look quite pale.”

Okay. He could do this. It was Aine’s voice, but the tone made it sound so different.

Reiji plastered his most welcoming smile as he held his hand out towards Ai.

“Allow me to introduce myself properly, your Highness. Prince Reiji, second heir to the Kotobuki line. It’s an honour to finally meet you, Prince Ai.”

Ai firmly took his wrist for a formal shake. His hand was cold, whereas Aine’s had been warm, so warm, until…

Don’t think about it.

“Likewise, it is an honour to meet you, Prince Reiji. Aine always talked about you with such high regards.”

Reiji wished he could say the same, but up until the king’s letter, he had been unaware of Ai’s very existence. It must have shown on his face, for Ai carried on.

“Do not worry. It is of no surprise that my brother has failed to mention my existence. My birth has been kept secret for years.”

Reiji blinked at the rather odd explanation.

“Really? Might I enquire as to why? Unless, that too must be kept secret.”

“I see no reasons why it should be, seeing as I am standing here, in front of you. My parents have always feared their children would be targeted from birth. Like you, I was the spare, as a result my existence has been kept a secret so that, would anything befall my brother the crown prince, the Kisaragi line may live on through me.”

Ai spoke in such a matter-of-fact voice, it unnerved Reiji to no end. It also seemed to unnerve Otoya, his eyes having become wide as saucers.

“I… see. One could say their royal Majesties have acted wisely.”

“I think it’s bothersome more than anything.” Ai answered back.

The young prince’s hand dropped and he returned to his seat beside the blond advisor, the latter already holding a cup of tea in hand.

Not knowing how to answer, Reiji sat down on the couch facing them, between his advisor and his young protégé. He couldn’t see it, but he could feel a tall intimidating presence behind the couch, and he knew for sure that Ranmaru had taken his place behind him.

He could do this.

Ai wasn’t Aine.

He could do this.

* * *

_Reiji._

_Reeeeeiiiiijiiiiiiii._


End file.
